Nanocapsules comprising (semi-) liquid lipid core and solid lipid shell, prepared by phase inversion methods, useful for administration of lipophilic or hydrophilic drugs by injection, orally or intranasally

摘要

Novel nanocapsules (I) of average size less than 150 nm (preferably less than 50 nm) consist of a lipid core which is liquid or semi-liquid at ambient temperature and a lipid coating film which is solid at ambient temperature. An Independent claim is included for the preparation of nanocapsules, by steps (a-c): (a) preparing an oil-in-water emulsion containing an oily lipid phase, a hydrophilic nonionic surfactant, a lipophilic surfactant which is solid at 20 deg C and optionally a drug which is soluble or dispersible in the lipid or aqueous phase; (b) causing phase inversion by heating to a temperature T2 above the phase inversion temperature (PIT) to give a water-in-oil emulsion then re cooling to a temperature T1 below the PIT, one or more such cycles being carried out until a translucid suspension is obtained; and (c) tempering the oil-in-water emulsion at a temperature close to (preferably above) T1 to give stable nanocapsules.